Rates on US Treasury bills flat to higher in weekly auction

Interest rates on short-term Treasury bills were flat to higher in Monday's auction, with six-month bills reaching their highest level in three weeks.

The Treasury Department auctioned $34 billion in three-month bills at a discount rate of 0.490 percent, unchanged from last week. Another $28 billion in six-month bills was auctioned at a discount rate of 0.615 percent, up from 0.610 percent last week.

The six-month rate was the highest since those bills averaged 0.625 percent on Nov. 14.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,987.61, while a six-month bill sold for $9,969.20. That would equal an annualized rate of 0.497 percent for the three-month bills and 0.625 percent for the six-month bills.

Separately, the Federal Reserve said Monday that the average yield for one-year Treasury bills, a popular index for making changes in adjustable-rate mortgages, rose to 0.80 percent last Friday after starting last week at 0.79 percent.